Regulating device for compressed fluid generators of the free pistons type



y 14, 1940- R.-PATERAS PESCARA 2.200.892

REGULATING DEVICE FOR COMPRESSED FLUID GENERATORS OF THE FREE PISTONTYPE Filed Nov. 3, 1936 5 Sheets-Sheet 1 FUEL Pum I A35 4 9 o J61flea/ms i i s U Mid (5 Affar/ve 1 5 y 1940. R. PATERAS PESCARA 2200.892

REGULATING DEVICE FOR COMPRESSED FLUID GENERATORS OF THE FREE PISTONTYPE Filed NOV. 5,-1936 5 Sheets-Sheet 2 i 5 Wed/N5 no, I 27 25 2 a? J21 4 l l i y 1940- R. PATERAS PESCARA 2.200.892

REGULATING DEVICE FOR COMPRESSED FLUID GENERATORS OF THE FREE PISTONTYPE Filed Nov. 3, 1956 3 Sheets-Sheet 3 Patented May 14, 1940 UNITEDSTATES PATENT OFFICE REGULATING DEVICE FOR COMPRESSED FLUID GENERATORSOF THE FREE PIS- TONS TYPE land Application November 3, 1936, Serial No.109,033 In Belgium November 8, 1935 16 Claims. (01. 60-13 The presentinvention relates to regulating devices for compressed fluid generatorsof the type having free pistons, adapted to feed fluid under variablepressure of operation to receiving machines such as turbines.

Compressed fluid generators of the type above mentioned include ascavenging arrangement working at variable feed pressure, the whole or apart of the compressed fluid being caused to flow through the engine forperforming the scavenging operation. The excess of the scavenging gaseswhich, in this case, merely passes through the engine, forms with theexhaust gases a mixture at a relatively low temperature which may beused advantageously for operating at least one receiving machine, suchas a turbine.

The object of the present invention is to provide a regulating device ofthe type above referred to which permits of obtaining a correct feed ofthe receiving machine under variable loads and in accordance with theknown characteristics of said receiving machine, which characteristicsdetermine the corresponding variations of pressure and rate of feed ofthe compressed fluid.

The essential feature of the present invention' consists, in systems ofthe kind above referred to including a compressed fluid generator thepistons of which are capable of undergoing considerable variations ofstroke, in exerting the regulating action exclusively on the feed offuel to the motor cylinder, at least for normal conditionsof Working ofthe generator.

Another important feature of the present invention consists insubjecting the means for controlling the rate of feed of fuel to thecompressor motor cylinder to the action of both a regulating deviceresponsive to variations of the pressure of the fluid supplied to thereceiving machine and a speed regulating device driven by said receivingmachine. The connections between said fuel feed control means and theseregulating devices respectively may be positive for both of them or theymay be arranged in such manner that at least one of said connectionsleaves the regulating device corresponding to the other connection freeto act within certain limits and serves to correct the action thereofonly outside of said limits.

Other features of the present invention will result from the followingdetailed description of some specific embodiments thereof.

Preferred embodiments of the present invention will be hereinafterdescribed, with reference to the accompanying drawings, given merely byway of example, and in which:

Fig. 1 is a longitudinal sectional view of a system including acompressed fluid generator of the free piston and variable pressure typeand a a third embodiment of the invention;

Fig. 6 shows, in a manner similar to Fig. 1, a portion of a system ofthe same kind, but in which the regulating device is made according to afourth embodiment of the invention;

Fig. '7 is a diagram illustrating the operation of the last mentionedembodiment;

Fig. 8 is a perspective view showing a regulating device made accordingto a modification of that of Fig. 6;

' Fig. 8a is a cross section through the slide valve of Fig. 8;

' Fig. 9 shows, in a manner similar to Fig. 1, a portion of a system ofthe same kind, but in which the regulating device is made according to afifth embodiment of the invention.

In the following description, it will be supposed that a compressedfluid generator of the free piston type is arranged to feed a fluidunder pressure to a receiving machine, such as a turbine, the regulatingdevice according to the invention being applied to said generator.

Concerning the generator of the free piston type adapted to give avariable pressure (more especially an air compressor) it includes atwostroke engine with scavenging means. Said engine includes, forinstance, two pistons l and C of the single acting type, moving inopposite directions respectively in a motor cylinder 2. These motivepistons l and l are connected respectively with two compressing pistons3 and 3 working in distinct compression cylinders 4 and 4 respectivelyand delivering air into a compressed air reservoir 5.

This reservoir 5 is not directly connected with the receiving machine 6,for instance a turbine, but it is connected with the scavenging and airinlet orifices of generator 2 through a conduit 1,

in such manner that the whole of the compressed air flows through thegenerator so as to effect the scavenging thereof, only a portion of thisair being utilized for combustion, and the excess of the air that hasperformed the-scavenging being fed to the receiving turbine I at thesame time as the burnt gases.

Such an arrangement is known in the art, and it has been disclosed in avery simplified man'- ner in the drawings, but it should be wellunderstood that it might be modified or completed in various wayswithout in any way departing from the principle of the invention.

Concerning the feed of fuel to the compressed fluid generator, it willbe assumed, in the following description that the fuel is liquid andthat it is injected to cylinder! by means of a pump I actuated through acam mechanism Iii or the like, itself controlled by a movable element ofthe generator itself, this pump I feeding the fuel into a conduit llconnected to the injection device, or devices, I! of the engine.

Pump I of the usual Bosch type is provided with an element II forregulating the amount of fuel fed and delivered to the engine. Thiselement II may consist, in the usual manner, of a slide valve.

In the conduit I, extending between the gen-' erator cylinder 2 and thereceiving machine I, and in which the pressure is the delivery pressure,there is provided passage lib communicating with the interior of acylinder IIa in which is arranged a movable or deformable element, forinstance a piston II with a return spring llc, a manometric deformablebox or the like, which is connected to a piece having a suitableoutline, pivoted about a fixed pivot Il such as an oscillating cam II,acting upon the regulating element ll of the pump. The outline of thiscam is given a shape such that; through its action upon element II, thevariations of feed of fuel, corresponding to variations of pressure, arethe same for generator 2 and receiving machine I. That is, thevariations in fuel quantity delivered to the motor compressor are suchthat they produce, in the pressure and quantity of drive gas, variationscorresponding to the quantity and pressure requirements of the drivenmachine or turbine. These variations in the requirements of the drivenmachine or turbine are caused, of course, by variations in the load uponthe driven machine or turbine. When the load on the turbine increases, aback pressure caused thereby also increases, and thus produces anincrease in pressure in the gas feed line. This causes an increase inthe feed of fuel. When the charge of fuel is increased, the pressure andvolume of the gas produced are likewise increased, to compensate for theincreased load. In the device as shown, the pressure in the cylinderI311. moves piston i3 against spring He, thus turning cam II and movingcontrol rod II of the pump 8. The feed of the pump is thus varied inresponse to variations in pressure in the outlet conduit 8. The outletpressure is increased or decreased upon increase or decreaserespectively of the load on turbine I. The pressure and the quantity ofthe gases in the conduit I are thus increased or decreased upon increaseor decrease respectively of the load on the turbine I, so as tocompensate for changes in this load.

This automatic regulation of the feed of fuel as a function of thepressure existing in the feed conduit of the receiving machine, andtherefore as a function of the load thereof is not always sufficient forensuring a correct and smooth working of the system at low speeds of thereceiving machine.

It is known, in fact, that for all the working pressures of thegenerator, a certain minimum of air feed is absolutely necessary forensuring the scavenging of the engine, and, furthermore, that themachine can work only for strokes of the pistons ranging within twolimits, one of which, the minimum limit, 1", corresponds to the minimumopening of the distribution orifices of the motive cylinder 2, that is,the smallest stroke that will uncover the openings of passages l and Iwhile the other one, the maximum limit I", is determined by conditionsof safety.

In Fig. 2, I have shown a diagram in which the pressures are plotted inordinates and the strokes in abscissas, this diagram corresponding tothe compressing portion of the generator. In this figure, I have shownthe values of the limit strokes l and I", and also certaincharacteristic working curves AB, D C and DC of this compressingportion. The feed of air that is assumed to be absolutely necessary forensuring the scavenging of the engine is shown by B 0 B'C", etc. Betweenpressures 12 and 9 the movable parts or pistons of the generator mustmove a distance at least equal to 1 and the feed 3 C decreases as thepressure increases. For pressure p the feed B C corresponds to theminimum feed necessary for the scavenging of the motive cylinder. Forpressures higher than 12*, the minimum feed such as 3 0 must always bemaintained for ensuring the scavenging of the engine and for thispurpose, stroke Ac becomes greater than the minimum stroke 1 In thediagram of Fig. 3, the pressures are plotted in abscissas and the volumeor amounts of fluid in ordinates. In this diagram, I have shown at I thecurve representing the variation,

of the amount of fluid fed by generator 2 as a function of the pressurefor the minimum feed of fuel injected for each value of the pressure.

The maximum amount of fuel-injected for each value of the pressure, thatis to say the amount corresponding to the maximum stroke 1", isindicated by curve I, which shows the quantitative variation of theamount of fluid under pressure fed by generator 2.

Between these two curves, it suffices to inject, for each pressure, thesuitable amount of fuel, and the rate of delivery of the generator isexactly equal to the amount absorbed by the receiving machine at thesame pressure, the characteristic curve for the receiving machine beingshown at II in Fig. 3.

It is found that the rate of delivery of the generator can be made tocorrespond to the amount required by the receiving machine only betweenpoints N and M of curve II, these points being those where thecharacteristic curve II of the receiving machine intersects thecharacteristic limit-curves 0f the generator corresponding to theminimum and maximum strokes.

According to the present invention, I make use of the some element II,responsive to the variations of the pressure on the delivery side of thegenerator, between said generator and the receiving machine I, foradjusting to each other the rates of flow from the generator and to thereceiving machine respectively, as well for loads included betweenpoints M and N as for lower loads MS corresponding to rates of feed ofthe receiving machine lower than the limit rates of u delivery of thegenerator indicated by the curve I of Fig. 3.

For this purpose, I may allow the generator to produce, at lowpressures, an amount of fluid such as Rr, which corresponds to itsworking with a minimum injection of fuel, and allow the excess RS whichcannot be absorbed by the receiving machine to escape outwardly. In thiscase, I determine exactly the excess or supplementary amount, such asRS, by variably opening an escape valve i6 (Fig. 1) provided on theconduit 8 before the receiving machine 6. This valve l6, subjected tothe action of its return spring I6 is located for instance opposite therod ll of piston IS in such manner that said valve is opened when theend of rod I1 is applied thereon. The whole of the device is arranged insuch manner that the opening of valve i6 takes place for a pressure mcorresponding to the point M of the diagram of Fig. 3.

I may also automatically regulate, through the medium of a distributionmember controlled by the pressure, the amount of compressed air that isdelivered at low pressures in such manner that generator 2 supplies, forits minimum geometrical stroke 1 (Fig. 2) an amount of air strictlysuflicient for the scavenging of the engine (curve A S B of Fig. 3).

In order to obtain this result, it suffices to limit for instance theintake stroke or the compression stroke of the compressors. Thislimitation of the production of compressed air can be obtained, as shownby Fig. 4, by causing the rod ll of piston l3 to act, for instancethrough an equalizing bar I8, upon a sliding element or valve 20. Thisslide valve 20, by covering more or less an orifice 2| provided in thewall of each of the compression cylinders 4 and 4*, permits of delayingmore or less the beginning of the compression stroke so as tocorrespondingly vary the amount of air compressed by said compressors.

In the case, already considered for the embodiment of Fig. l, in which aportion of the gases .produced by the generator is allowed to escape Forthis purpose, as shown by Fig. 5, I may cause the excess of scavengingair to flow through a circuit such as l9-22 in which there is insertedan automatic distributing device, for instance a sliding valve 23,subjected to the pressure existing in conduit i9. This sliding valve 23also plays the part of the piston i3 of Fig. 1 and acts, through its rodll, upon cam I5 for controlling the amount of fuel that is injected.According to the position occupied by sliding element 23 under theeifect'of the pressure existing in reservoir 5 and in conduit IS, thesupplementary amount of scavenging air flows either through the centralconduit 26, orifice 24, groove 26 and conduit 22, to the receivingmachine 6 without passing through the engine 2, or through centralconduit 26 and orifice 21 to the atmosphere. As soon as the pressure hasbecome sufilciently high in reservoir 6, sliding element 23 fully stopsconduit 22 and'orifice 21 and the whole of the compressed air flowsthrough the engine.

When the receiving machine is subjected to important variations of load,the regulation resulting merely from pressure variations may be too slowas a consequence of the cushioning mass of compressed fluid stored up inthe scavenging reservoir 5 of the generator and in the conduits such as3 and I9 leading to the receiving machine. As a certain temporaryvariation of the speed of the receiving machine can generally beadmitted when there is a variation of the load, I may also bring intoplay, for regulating the rate of delivery of the generator, a speedregulator which is associated with the receiving machine 6, and Iprovide, according to the present invention, means for combining theaction of this last mentioned regulator with that of the pressureresponsive regulating device l3 of the kind of those above described.

For instance, and as shown in Fig. 6, I may connect, either directly orpreferably through a relay, the speed regulator, or centrifugal governor28 of the receiving machine 6 with the cam i5 which controls the memberit through which the feed pump 9 is controlled. This cam i5 issimultaneously subjected to the action of the pressure responsiveregulator, such as piston [3, the cylinder of which is connected to aconduit 29 extending between generator 2 and receiving machine 6. Forinstance, the speed regulator acts through a pivoting connection uponcam l5 and the pressure responsive regulator acts through anotherpivoting connection upon said cam. Each pivoting connection constitutesan axis of rotation about which cam i5 can move angularly when it issubjected to an action from the regulator corresponding to the otherpivot.

In the embodiment illustrated by Fig. 6, the centrifugal governor 28 isdriven by the shaft 30 of the receiving machine or turbine 6. Thisgovernor acts, through a slide valve 3i, upon a hydraulic relayincluding a piston 32 connected with cam. i5 through a rod 33. Duringthe permanent or normal working of receiving machine 6, piston 32 issubjected, on both of its faces, to equal pressures, owing to theprovision of a small calibrated orifice 34 extending throughout piston32. When there is a variation of speed, producing for instance anacceleration, of the receiving machine, the centrifugal governor 28causes slide valve 3| to move, for instance toward the right of Fig. 6.This places tube 35, connected with a source of fluid under pressure,into communication with a conduit 36 leading to the cylinder of thepiston 32 of the relay. The

fluid under pressure pushes piston 32 toward the left hand side of Fig.6, which produces an angular displacement of cam IS in a direction whichcorresponds to member I reducing the amount of fuel injected into thecylinder of the generator. The cylinder of valve 3| is open at one endand near its other end has an opening 36 The pressure responsiveregulator i3 can be brought into play either subsequently orsimultaneously for reinforcing or reducing the action of the speedregulator upon the rate .of feed of fuel injected to the engine,producing an angular displacement of cam IS in one direction or theopposite one.

In the case of a reduction of the speed of receiving machine 6, thecentrifugal governor 28 moves toward the left hand side of Fig. 6, whichpermits the fluid under pressure, acting through tube 36, to quicklypush the .piston 32 of the relay toward the right hand side of Fig. 6.This produces an angular displacement of cam II in a direction forwhich, through its action upon control member H, the rate of, feed offuel injected to the generator is increased.

The pressure responsive regulator I3 is then brought into play forreinforcing or reducing the quick action of the speed regulator 28.

In the diagram shown in Fig. 'l, the pressures are plotted in abcissesand the amounts of fluid delivered are plotted in ordinates. I and I arecurves corresponding, respectively, to the minimum and maximum deliveryof gas under pressure and II is the characteristic curve of operation ofthe receiving machine 6.

Fig. 7 illustrates the regulating processes which take place when themomentary load of the turbine varies, said load being characterised, forexample, by the point P of the curve It.

If the load of the turbine is reduced, for example, an acceleration ofthe governor 28 takes place. The acceleration of the governor 28influences the control of the injection pump 9 by reducing the amount offuel injected. This reduction of the amunt of fuel injected immedlatelycauses the length of stroke of the freelyreciprocating pistons to beshortened and thus the amount of propelling gas to be reduced, whereasthe decrease in pressure only takes place gradually. The immediatereduction of the amount of gas is shown in Fig. 7 by the dotted line PP. Gradually, however, a lowering of pressure also takes place. Thislowering of pressure influences the control member of the injection pumpin such a manner that the amount injected is still further reduced.Thus, a fresh reduction of the amount of gas takes place simultaneouslywith the reduction of the gas pressure. This change is indicated in Fig.7 by the line PP. The point P however, is really too low, i. e., theregulation has been too extreme (over-adjustment). The result is thatthe turbine, which previously ran too fast, reduces its speed. Thiscauses the governor 28 to influence the fuel adjustment by increasingthe amount of fuel. By increasing the amount of fuel, the amount ofpropelling gas and the gas pressure are also increased. Consequently,the amount and pressure of the gas rise according to the line P P. Whenthe point P is reached, the condition of equilibrium between the amountof injected fuel and the load of the turbine, which load is reducedrelatively to the point P is again obtained.

The same operation would take place, but in the opposite direction, inthe case of an increase 01' the load producing a temporary slowing downof the receiving machine.

When the receiver is liable to undergo instantaneous and importantvariations of the load, for instance from the maximum load to theconditions of running under no load, and inversely, it is advantageous,especially in the case of turbines, to effect a quick regulation of thegenerator in order to avoid too important a racing and too considerablea slowing down of receiving device 6. As a limited variation of theworking speed is generally admitted, it is possible to eilect theregulation of the generator, between two limits which correspond to eachdelivery pressure, by means of the speed regulator of the receivingmachine, and to automatically vary these limits as a function of saidvariable delivery pressure.

For instance, and as shown by Fig. 8, it is possible to control themember I4 of the injection pump I by means of the centrifugal governor2! of the receiving device, for instance through the medium of apneumatic relay 31,

ano es:

provided with its slide-valve as shown at 3|a. in Fig. 8 controlled byrod 61. This slide valve (Fig. 8a) includes a piston it connected to rod6| for selectively connecting a discharge passage 65 to passages 63(connected to a supply of fluid under pressure) and H (connected tocasing 2|), and connecting passages 63, 54 to each other throughpassages 62 in piston 60. The flange at the left end of the piston 60can, when properly positioned, close oil. passage 64.

If the rotation of 'the turbine increases because of an increase in thefuel supply, the governor 28 shifts the piston 60 towards the left. Theconduit 64 is thus shut off from the pressure supply pipe 63, and isconnected to discharge pipe 65. The oil under pressure then escapes fromthe casing 31 which contracts because of the elasticity of the walls andthus adjusts the control rod I of the pump 9 so as to reduce the supplyof fuel. When a state of balance is reached, the flange at the left endof the piston 60 covers the conduit 64 so that no passage of fluid takesplace through the casing.

If the speed decreases, the piston 60 moves to the right and connectspipe 63 through passages 62 with pipe 64, at the same time closing offcommunication between pipes 64 and 65, thus supplying fluid underpressure to the casing 31 to increase the fuel supply. This serves tolimit the displacements of member H, for each working pressure, to twoextreme values which correspond to the limit rates of delivery of thegenerator for this pressure. Forinstance, I limit the angulardisplacement of control lever 38, provided between pneumatic relay 3'!and member M, by means of at least one abutment, the position of whichcan be modified by the pressure responsive regulator 13, which, in thisembodiment, consists of a manometric deformable box.

For this purpose, said lever 38 may be provided with a pin or lug 39which is engaged in a slot 40 provided in an oscillating piece 4|subjected to the action of the pressure responsive regulator.

The edges of slot 40, adapted to cooperate with pin or lug 29, are givena suitable outline. Slot 40 might be replaced by a kind of fork, alsocarried by member 4|, and between the branches of which pin 39 would beengaged.

. In this emodiment, I obtain, for small variations of load, a variationof the amount of fuel injected into the cylinder of the generator, underthe effect of the speed regulator 28 alone. The pressure variation canthus be established slowly without influencing the regulation sinceoscillating member 4| can come into contact with pin 39 only forimportant displacements of member ll.

When there is an important variation of the load, the speed regulator 28first produces the displacement of control member I as far as the limitcorresponding to the contact of pin 39 with the edge of the slot 40provided in piece H, in one direction or the other. This piece 4| thenmoves as a function of the pressure existing in the conduit 8 in whichthe generator delivers the gases under pressure, and as this pressurevaries, there is obtained a position of equilibrium corresponding to thenew load conditions.

At the same time as I obtain the regulation of the amount of fuelinjected into the engine, I may also, according to the presentinvention, automatically and simultaneously regulate the point ofinjection and the position of the injection nozzles with respect to thecombustion chamber.

The form of the invention shown in Fig. 9 embodies this principle. Themotor compressor shown in this figure is similar to that previouslydescribed, driving the turbine 6 through the outlet 8. The motorcylinder 2, however, includes an injection mechanism I! having dischargepassages arranged in a V, this fuel feed member being mounted forturning about an axis transverse to the longitudinal axis of thecylinder.

Provided in the reservoir 5 is an outlet controlled by a valve -memberIlla which is connected by a rod I! to a piston l3, the other side ofwhich is acted on bythe pressure in outlet passage 8 through aconnecting passage. Thus when the pressure in the discharge outlet dropstoo low, piston I! will be moved to the right and will open valve 20a torelieve the pressure in the reservoir 5.

Element I3 is connected to rod l1 and thus to piston l3 by a lever 45,and carries a roller resting on the short arm of lever Ill. The free endof member 43 engages the rod 42 which by its movement feeds fuel fromthe pump 9. The position of piston l3 will thus vary the position -ofthe roller and the degree of movement of rod 42 so as to vary the feedof fuel thereby.

The feed of fuel is also controlled by the rod l4, operated by cam l5and controlled jointly by pistons l3 and 32 in the same manner as inFig, 6.

Finally, lever 4| which connects piston ii to cam also is connected toarm 48 rigid with the turnable fuel injection member II. when thepressure decreases, this fuel injection member is in the position shownin Fig. 9 and the diverging discharge openings thereof operate the fuelover a considerable area longitudinally of the cylinder. When, on theother hand, the pressure increases, and piston I3 is moved to the left,member I! is turned thereby until the V is at right angles to thelongitudinal axis of the cylinder, whereupon the jets of fuel areoperated in the same transverse plane. Thus the distribution of the fuellongitudinally of the motor cylinder is controlled.

In a general manner, while I have, in the above description, disclosedwhat I deem to be practical and eflicient embodiments of thepresentinvention, it should be well understood that I do not wish to belimited thereto as there might be changes made in the arrangement,disposition and form of the parts without departing from the principleof the present invention as comprehended within the scope of theappended claims.

What I claim is:

l. A system of the type described which comprises, in combination, amotor compressor including an internal combustion motor cylinder, atleast one gas compression cylinder, at least one piston freely movablein said cylinders, and an adjustable pump for feeding fuel to said,motor cylinder, 2. gas operated receiving machine requiring at lowdrive gas pressures a quantity of gas less than the minimum output ofsaid motor compressor, means for causing gas under pressure from saidcompression cylinder to flow to said receiving machine by passing atleast partly through said motor cylinder, said means being arranged toconvey, under normal running conditions of the system, the whole of saidgas to said receiving machine, regulating means, responsive tovariations of the working conditions of said receiving machine, forcontrolling the feed of said fuel pump, and outlet means disposedbetween the inlet of the compressor cylinder and the gas operatedreceiving machine operative by the pressure of the compressed gas, atlow pressures only of the compressed gas, for releasing a part of thegas after its entrance into the compressor cylinder.

2. A system of the type described which comprises, in combination, amotor compressor including an internal combustion motor cylinder, atleast one gas compression cylinder, at least one piston freely movablein said cylinders, and an adjustable pump for feeding fuel to said motorcylinder, a gas operated receiving machine requiring at low drive gaspressures a quantity of gas less than the minimum quantity of gasdelivered by said motor compressor, means for causing gas under pressurefrom said compression cylinder to flow to said receiving machine bypassing at least partly through said motor cylinder, said means beingarranged to convey, under normal conditions of the system, the whole ofsaid gas to said receiving machine, regulating means, responsive tovariations of the working conditions of said receiving machine, forcontrolling the feed of said fuel pump, valve means, normally closed,for connecting a point of the path of the gas under pressure betweensaid compression cylinder, inclusive, and said receiving machine, withan atmosphere at a pressure lower than that of said gas under pressure,and means, operative by the gas under pressure, for opening said valvemeans at low admission pressures of the receiving machine.

3. A system of the type described, which comprises, in combination, amotor compressor including an internal combustion motor cylinder, atleast one gas compression cylinder, at least one piston freely movablein said cylinders, and an adjustable pump for feeding fuel to said-motorcylinder, a gas operated receiving machine requiring. at low gaspressures a quantity of gas less than the minimum quantity delivered bysaid motor compressor, means for causing gas under pressure from saidcompression cylinder to flow to said receiving machine by passing atleast partly through said motor cylinder, said means being arranged toconvey, under normal running conditions of the system, the whole of saidgas to said receiving machine, a piston movable in response tovariations of the pressure of the gas under presssure at a point of thepath thereof between said compression cylinder, inclusive, and saidmachine, for controlling the feed of said fuel pump, valve meansnormally closed, for connecting a point of the path of the gas underpressure between said compression cylinder, inclusive, and saidreceiving machine, with an atmosphere at a pressure lower than that ofsaid gas under pressure, said valve means bein opened by thesecond-mentioned piston at low admission pressures of the receivingmachine.

4. A system of the type described, which comprises, in combination, amotor compressor including an internal combustion motor cylinder,

sion cylinder to flow to said receiving machine by passing at leastpartly through said motor cylinder, said means being arranged to convey,

under normal running conditions of the system, the whole of said gas tosaid receiving machine, a piston movable in response to variations ofthe pressure of the gas under pressure at a point of the path thereofbetweensaid compression cylinder, inclusive, and said receiving machine,for controlling the feed of said fuel pump, and means operative by saidsecond mentioned piston, for reducing the useful stroke of the firstmentioned piston at low admission pressures of the receiving machine toreduce the quantity of gas delivered below such minimum.

5. 'A system of the type described according to claim 4, in which saidcompression cylinder is provided with a longitudinal slot, the lastmentioned means of claim 4 consisting of a sliding member, operativelyconnected with said second mentioned piston, for covering said slotunder predetermined conditions.

6. A system of the type described, which comprises, in combination, amotor compressor including an internal combustion motor cylinder, atleast one gas compression cylinder, at least one piston freely movablein said cylinders, and an adjustable pump for feeding fuel to said motorcylinder, a gas operated receiving machine, means for causing gas underpressure from said compression cylinder to flow to said receivingmachine by passing at least partly through said motor cylinder, saidmeans bein arranged to convey, under normal rimning conditions of thesystem, the whole of said gas to said receiving machine, regulatingmeans, responsive to variations of the pressure of the gas underpressure at a point of the path thereof between said compressioncylinder, inclusive, and said receiving machine, for controlling thefeed of said fuel pump, and regulating means, responsive to variationsof the speed of said receiving machine, also for directly controllingthe feed of said fuel pump.

'7. A system of the type described which comprises, in combination, amotor compressor including an internal combustion motor cylinder,

at least one gas compression cylinder, at least one piston freelymovable in said cylinders, and an adjustable pump for feeding fuel tosaid motor cylinders, a gas operated receiving machine, means forcausing gas under pressure from said compression cylinder to flow tosaid receiving machine by passing'at least partly through said motorcylinder, said means being arranged to convey, under normal runningconditions of the system, the whole of said gas to said receivingmachine, means for controlling the feed of said fuel pump, regulatingmeans, responsive to variations of the pressure of the gas underpressure at a point of the path thereof between said compressioncylinder, inclusive, and said receiving machine, and regulating means,responsive to variations of the speed of said receiving machine, forboth directly operating said piunp feed control means.

8. A system according to claim 7 in which said fuel pump feed. controlmeans include a cam adapted to cooperate with said pump, each of the tworegulating means including an operating member pivotally connected tosaid cam.

9. A system according to claim 7 in which said fuel feed control meansinclude a cam adapted to cooperate with said pump, the first mentionedregulating means including a piston subjected to the action of said gaspressure and a rod carried by said piston pivotally connected with saidcam, and the second mentioned regulating means including a centrifugalgovernor operatively connected with said receiving machine, a memberpivotally connected with said cam, and a hydraulic relay interposedbetween said governor and said member.

10. A system of the type described which comprises, in combination, amotor-compressor including an internal combustion motor cylinder atleast one gas compression cylinder, at least one piston freely movablein said cylinders, and an adjustable pump for feeding fuel to said motorcylinder, a gas operated receiving machine, means for causing gas underpressure from said compression cylinder to flow to said receivingmachine by passing at least partly through said motor cylinder, saidmeans being arranged to convey, under normal running conditions, of thesystem, the whole of said gas to said receiving machine, regulatingmeans, responsive to variations of the speed of said receiving machine,for controlling the food of said fuel pump, and regulating means,responsive to variations of the pressure of the gas under pressure at apoint of the path thereof between said compression cylinder, inclusive,and said receiving machine, for varying the limits of action of saidfirst mentioned regulating means.

11. A system according to claim 10 in which the first mentionedregulating means include a centrifugal governor operatively connectedwith said machine, a member for controlling the feed of said pump, apivoting lever for actuating said member, and a relay interposed betweensaid lever for interconnecting them, and the second mentioned regulatingmeans include a part movable in response to variations of said pressure,a movable element adapted to limit the displacements of said lever inaccordance with the position of said element, and means forinterconnecting said part and said element.

12. A system of the type described, which comprises, in combination, amotor compressor including an internal combustion motor cylinder, atleast one gas compression cylinder, at least one piston freely movablein said cylinders and an adjustable pump for feeding fuel to said motorcylinder, a gas operated turbine, means for causing gas under pressurefrom said compression cylinder to flow to said turbine by passing atleast partly through said motor cylinder, said means being arranged toconvey, under normal conditions of the system, the whole of said gas tosaid turbine, regulating means, responsive to variations of the workingconditions of said turbine for controlling the feed of said fuel pump,valve means, normally closed, for connecting a point of the path of thegas under pressure between said compression cyland an adjustable pumpfor feeding fuel to said motor cylinder, a gas operated turbine, meansfor causing gas under pressure from said compression cylinder to flow tosaid turbine by passing at least partly through said motor cylinder,said means being arranged to convey, under normal conditions of thesystem, the whole of said gas to said turbine, regulating means,responsive to variations of the working conditions of said turbine forcontrolling the feed of said fuel pump, and gas pressure responsivemeans operative at low admission pressures of said turbine for releasingfrom said compression cylinder during the compression stroke thereof.part of the gas in said compression cylinder at pressures below thedelivery pressure of said last-named cylinder.

14. A system of the type described, which comprises, in combination, amotor compressor including an internal combustion motor cylinder. atleast one gas compression cylinder, at least one piston freely movablein said cylinders, and an adjustable pump for feeding fuel to said motorcylinder, a gas operated turbine. means for causing gas under pressurefrom said compression cylinder to flow to said turbine by passing atleast partly through said motor cylinder, regulating means, responsiveto variations of the pressure of the gas under pressure at a point ofthe path thereof between said compression cyl inder. inclusive, and saidturbine for controlling the feed of said fuel pump, and regulatingmeans. responsive to variations of the speed of said turbine forcontrolling directly the feed of said fuel pump.

15. A system of the type described which comprises, in combination, amotor-compressor including an internal combustion motor cylinder. atleast one gas compression cylinder, at least one piston freely movablein said cylinders and an adjustable pump for feeding fuel to said motorcylinder, a gas operated turbine, means for causing gas under pressurefrom said compression cylinder to flow to said turbine. by passing atleast partly through said motor cylinder. regulating means, responsiveto variations of the speed of said turbine for controlling the feed ofsaid fuel pump, and regulating means, responsive to variations of thepressure of the gas under pressure at a point of the path thereofbetween said compression cylinder inclusive, and said turbine forvarying the limits of action of said first mentioned regulating means.

16. A system of the type described which comprises in combination, amotor compressor including an internal combustion motor cylinder, atleast one gas compression cylinder, at least. one piston freely movablein said cylinder, and an adjustable pump for feeding fuel to said motorcylinder, a gas operated turbine, requiring at low drive gas pressures aquantity of gas less than the minimum output of said motor compressormeans for causing gas under pressure to flow from said compressioncylinder to said turbine by passing at least partly through said motorcylinder, regulating means responsive to variations of the pressure ofthe'gas entering said turbine and capable of controlling the feed ofsaid fuel pump under normal running conditions in such manner that theamount of the gas under pressure increases when the pressure increases.and vice versa, and outlet means disposed between said compressioncylinder and said turbine and capable of reducing. at low pressures onlyof thecompressed gas, the quantity of said gas.

RAUL PATERAS PESCARA.

Certificate of Correction Patent No. 2,200,892. May 14, 1940.

RAUL PATERAS PESCARA It is hereby certified that error appears in theprinted specification of the above numbered patent requiring correctionas follows: Page 6, second column, line 37, claim 11, after the wordbetween insert said governor and; and that the said Letters Patentshould be read with this correction therein that the same may conform tothe record of the case in the Patent Ofiice.

Signed and sealed this 13th day of April, A. D. 1948.

THOMAS F. MURPHY,

Assistant Gammissioner of Patents.

